I suspect I have a 'bad spot' on my hardrive; CHKDSK gets to certain point, drive repeats a distinctive sound(twice); CHKDSK aborts, system reboots. Just after it "dies", there is a screen that flashes for a fraction of a second...DEFRAG, MALWARE, AD-AWARE...all crash and burn likewise. Old P4 system, small(40 gig) hard drive. Any suggestions for futher diagnosis, or should I recycle this dinosaur???